It just populates the list with strings.

This issue is not limited to D&D. It happens with all data. So if I just populate the list on showEvent() in MainWindow the same will happen. Data rows will show fine, but after resize the same will happen.

Would you mind trying your self? The entire code for QDragDropWidget is in my previous post. So just place QTableWidget in resizable layout and promote it to QDDW. I'm interested to see of anyone else has this issue.